The Petlyakov PE-8 prototype first appeared in December, 1936, although production models only went into service in 1940. Powered by four Mikulin AM-35A liquid cooled V-12 engines rated at 1,350 hp. each, the production PE-8 (known to Americans as TB-7) was 77 ft. 5 in. long and had a wing span of 128 ft. 3 in, considerably larger than the contemporary Boeing B-17. Armed with three powered turrets and two precariously mounted gun positions aft of the inboard engine nacelles (No. 2 and 3 engines), it was an advanced design at the time of its introduction. Featuring a maximum speed of 276 mph., the PE-8 was intended as a long range bomber, carrying 8,800 lbs. of bombs, although some could carry an 11,000 lb. "blockbuster".

Although a promising design, the PE-8 was not produced in large numbers, the VVS high command apparently thinking that emphasis should be given to the development of tactical rather than strategic types. Between 1936 and 1944, between 93 to 96 examples were completed. Although the major variants were powered by Mikulin liquid cooled engines, some examples were equipped with 1,850 hp. Shvetsov radials or Charomski M-30B or M-40 diesel engines. Neither of these variants was successful, and in general, the type was not developed to its potential. Although it was used for nuisance raids on Berlin starting in 1941, and for tactical operations against the German Army at Stalingrad and Kursk, its main claim to fame appears to be its epic May, 1942 flight from Russia through German controlled territory to London and Washington, D.C., carrying Foreign Minister Molotov for his highly publicized talks with British and American government officials concerning the opening up of a Second Front against the Germans.